#define __STDC_WANT_LIB_EXT__ 1
#include <stdio.h>
#include <assert.h>

int main(void){
  int y = 5;
  for(int x = 0 ; x < 20; ++x){
	printf("x = %d y = %d\n", x , y);  
	assert(x < y);
  }
  return 0;
}